1. Technical Field
The field of this invention is vascular disease, particularly vascular diseases characterized by the presence of calcified lesions, e.g. atherosclerosis, and the like.
2. Background of the Invention
The formation of plaques or lesions, (atherosclerotic plaques or lesions) on cardiovascular tissue, such as the inner surface of blood vessels, aortic valves, etc., is a major component of cardiovascular disease. Many atherosclerotic plaques and lesions are characterized by the presence of mineral deposits, i.e. they are calcified. Calcified lesion formation on prosthetic devices is also a problem in current cardiovascular disease treatment protocols. For example, calcification is an important limitation on the useful life expectancy of bioprosthetic valves, and accounts for over sixty percent of the cardiac bioprostheses failures.
A variety of different protocols have been developed for treating cardiovascular diseases associated with the presence of calcified lesions. Such treatment methodologies generally involve mechanical removal or reduction of the lesion, and include: bypass surgery, balloon angioplasty, mechanical debridement, atherectomy, valve replacement, and the like. Despite the plethora of different treatment strategies that have been developed for the treatment of cardiovascular disease, there are disadvantages associated with each technique, such as tissue damage, invasiveness, etc. For example, restenosis is a common complication that results in arteries in which lesions have been mechanically removed.
As such, there is continued interest in the development of new treatment protocols for the removal of vascular calcified lesions from vascular tissue. Of particular interest would be the development of a treatment protocol that is minimally invasive and/or results in minimal tissue damage.
Relevant Literature
U.S. Patents of interest include: U.S. Pat. Nos. 4,445,892; 4,573,966; 4,610,662; 4,636,195; 4,655,746; 4,824,436; 4,911,163; 4,976,733; 5,059,178; 5,090,960; 5,167,628; 5,195,955; 5,222,941; 5,380,284; 5,443,446; and 5,462,529.
Methods for at least reducing the mineral content of a calcified lesion on vascular tissue are provided. In the subject methods, the local environment of the target lesion is maintained at a subphysiologic pH for a period of time sufficient for the desired amount of demineralization to occur, e.g. by flushing the lesion with a fluid capable of locally increasing the proton concentration in the region of the calcified lesion. As a result, the mineral content of the calcified lesion is reduced. Also provided are kits and systems for practicing the subject methods. The subject invention finds use in a variety of different applications, including the treatment of vascular diseases associated with the presence of calcified lesions.